In various surgical procedures, it is necessary to dissect bone or other tissues. In some instances, it may be necessary to cut, grind, shape or otherwise remove hardened materials to make them ready for implantation or to remove them from a patient. Many conventional surgical instruments used for these purposes employ pneumatic or electrical motors to rotate a dissection element. In their most basic form, such a surgical instrument comprises a motor portion having a rotary shaft, a dissection tool having a cutting or abrading element that is rotated by the rotating shaft of the motor, and a coupling arrangement for connecting the dissection tool to a spindle or collet of the rotary shaft. The spindle or collet of the rotary shaft is usually housed within a base that is attached to the motor.
Since it is frequently necessary to replace the dissection tool, it is known in the art to use a quick release coupling to secure the dissection tool to the surgical instrument. An example of such a quick release coupling is shown and described in a commonly assigned U.S. Pat. No. 5,505,737, entitled “Quick Release Coupling For A Dissecting Tool,” incorporated herein by reference in its entirety.
While currently known surgical tools, including replaceable dissection tools, offer advantages over earlier designs, it remains desirable to further advance the pertinent art of coupling arrangements for the dissection tools. For example, during a surgical procedure, a dissection tool may rotate at high speeds, for example approximately 70,000 rpm, and it may not be effectively retained with previously available coupling arrangements under all operating conditions.